Assessment of the Right Ventricular Function and Mass Using Cardiac Multi-Detector Computed Tomography in Patients with Chronic Obstructive Pulmonary Disease

Objective

We wanted to assess the relationship between measurements of the right ventricular (RV) function and mass, with using cardiac multi-detector computed tomography (MDCT) and the severity of chronic obstructive pulmonary disease (COPD) as determined by the pulmonary function test (PFT).

Materials and Methods

Measurements of PFT and cardiac MDCT were obtained in 33 COPD patients. Using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, the patients were divided into three groups according to the severity of the disease: stage I (mild, n = 4), stage II (moderate, n = 15) and stage III (severe, n = 14). The RV function and the wall mass were obtained by cardiac MDCT. The results were compared among the groups using the Student-Newman-Keuls method. Pearson''s correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and the wall mass results with the PFT results. P-values less than 0.05 were considered statistically significant.

Results

The RVEF and mass were 47±3% and 41±2 g in stage I, 46±6% and 46±5 g in stage II, and 35±5% and 55±6 g in stage III, respectively. The RVEF was significantly lower in stage III than in stage I and II (p < 0.01). The RV mass was significantly different among the three stages, according to the disease severity of COPD (p < 0.05). The correlation was excellent between the MDCT results and forced expiratory volume in 1 sec (r = 0.797 for RVEF and r = -0.769 for RV mass) and forced expiratory volume in 1 sec to the forced vital capacity (r = 0.745 for RVEF and r = -0.718 for RV mass).

Conclusion

Our study shows that the mean RV wall mass as measured by cardiac MDCT correlates well with the COPD disease severity as determined by PFT.     

Comparison of capability of dynamic O₂-enhanced MRI and quantitative thin-section MDCT to assess COPD in smokers

Purpose

The purpose of this study was to directly and prospectively compare the capability of dynamic O₂-enhanced MRI and quantitatively assessed thin-section MDCT to assess smokers’ COPD in a large prospective cohort.

Materials and methods

The GOLD criteria for smokers were used to classify 187 smokers into four clinical stage groups as follows: smokers without COPD (n = 56) and with mild (n = 54), moderate (n = 52) and severe or very severe COPD (n = 24). All smokers underwent dynamic O₂-enhanced MRI, MDCT and pulmonary function tests. Mean relative enhancement ratio and mean wash-in time on MRI and CT-based functional lung volume (CT-based FLV) as well as the ratio of airway wall area to total airway area on MDCT were computationally calculated. Then, all indexes were significantly correlated with functional parameters. To determine the efficacy of all indexes for clinical stage classification, the indexes for the four clinical groups were statistically compared by using Tukey's honestly significant difference multiple comparison test.

Results

All indexes had significant correlations with functional parameters (p < 0.0001). All indexes except CT-based FLV in all groups had significant differences each other (p < 0.05).

Conclusions

Dynamic O₂-enhanced MRI for assessment of COPD in smokers is potentially as efficacious as quantitatively assessed thin-section MDCT.     

肺心病患者左右心功能的MRI研究

目的探讨MRI评价肺心病患者左、右心功能的应用价值。资料与方法前瞻性研究18例经肺功能实验、临床检查、X线、心电图、超声心动图等影像学检查证实为合并慢性阻塞性肺病(COPD)的肺心病患者,另选取18名健康志愿者作为对照组。采用1.5 T MRI仪测量两组左、右室心功能及右室心肌质量。采用独立样本t检验测量两组间差异是否有统计学意义。结果 2例肺心病患者MRI检查时由于屏气时间长、不能配合而排除。与对照组比较,16例肺心病患者右室(right ventricle,RV)舒张末期容积(end-diastolic volume,EDV)、右室收缩末期容积(end-systolic volume,ESV)及右室心肌质量(myocardial mass,MM)明显增加(P<0.05),而右室射血分数(ejec-tion fraction,EF)明显减低(P<0.01)。左室EDV及EF显著减低(P<0.01)。结论肺心病患者随着肺动脉压升高,超过右心室的代偿能力,促使右心室扩大和右心功能衰竭,同时左心功能损伤。MRI左右心功能的测量可以评价肺心病的严重程度,为临床提供治疗的客观依据。     

Quantitative bronchial luminal volumetric assessment of pulmonary function loss by thin-section MDCT in pulmonary emphysema patients

Objectives

To determine the capability of quantitative bronchial luminal volume to assess pulmonary function loss and disease severity in pulmonary emphysema patients.

Methods

Thirty-seven smokers (mean age, 68.1 years) underwent CT examinations and pulmonary function tests. For the quantitative assessment, luminal voxels of trachea and bronchi were computationally counted and the ratio of the following luminal voxels to all luminal voxels was obtained: (1) the lobe bronchi and the peripheral bronchi (Ratio_lobe), and (2) the main bronchi and the peripheral bronchi (Ratio_main). To determine the capability of these assessments to predict pulmonary function loss, these ratios were correlated with pulmonary function tests. To determine the capability for predicting disease severity, these ratios were compared between clinical groups.

Results

These ratios were no significant correlated with vital capacity and forced vital capacity (FVC) (p > 0.05), however significantly correlated with forced expiratory volume in 1 s (FEV1) (Ratio_lobe: r = 0.61, p < 0.0001, Ratio_main: r = 0.58, p < 0.0005) and FEV1/FVC (Ratio_lobe: r = 0.36, p < 0.05, Ratio_main: r = 0.33, p < 0.05). The Ratio_lobe of smokers without COPD was significantly different from those of moderate COPD and severe or very severe COPD (p < 0.05), while that of mild COPD was significantly different from that of severe or very severe COPD (p < 0.01). The Ratio_main of severe or very severe COPD patients was significantly different from those of other groups (p < 0.05).

Conclusions

Quantitative bronchial luminal volumes were reflected the airflow limitation parameters and was corresponded to clinical groups in emphysema patients.     

Quantification of left and right ventricular function and myocardial mass: comparison of low-radiation dose 2nd generation dual-source CT and cardiac MRI

Objective

To prospectively evaluate the accuracy of left and right ventricular function and myocardial mass measurements based on a dual-step, low radiation dose protocol with prospectively ECG-triggered 2nd generation dual-source CT (DSCT), using cardiac MRI (cMRI) as the reference standard.

Materials and methods

Twenty patients underwent 1.5 T cMRI and prospectively ECG-triggered dual-step pulsing cardiac DSCT. This image acquisition mode performs low-radiation (20% tube current) imaging over the majority of the cardiac cycle and applies full radiation only during a single adjustable phase. Full-radiation-phase images were used to assess cardiac morphology, while low-radiation-phase images were used to measure left and right ventricular function and mass. Quantitative CT measurements based on contiguous multiphase short-axis reconstructions from the axial CT data were compared with short-axis SSFP cardiac cine MRI. Contours were manually traced around the ventricular borders for calculation of left and right ventricular end-diastolic volume, end-systolic volume, stroke volume, ejection fraction and myocardial mass for both modalities. Statistical methods included independent t-tests, the Mann–Whitney U test, Pearson correlation statistics, and Bland–Altman analysis.

Results

All CT measurements of left and right ventricular function and mass correlated well with those from cMRI: for left/right end-diastolic volume r = 0.885/0.801, left/right end-systolic volume r = 0.947/0.879, left/right stroke volume r = 0.620/0.697, left/right ejection fraction r = 0.869/0.751, and left/right myocardial mass r = 0.959/0.702. Mean radiation dose was 6.2 ± 1.8 mSv.

Conclusions

Prospectively ECG-triggered, dual-step pulsing cardiac DSCT accurately quantifies left and right ventricular function and myocardial mass in comparison with cMRI with substantially lower radiation exposure than reported for traditional retrospective ECG-gating.     

Correlation of CT angiographic pulmonary artery obstruction scores with right ventricular dysfunction and clinical outcome in patients with acute pulmonary embolism

Objective

To correlate CTA pulmonary artery obstruction scores (OS) with right ventricular dysfunction (RVD) and clinical outcome in patients with acute pulmonary embolism (PE).

Materials and methods

In a prospective study of 50 patients (66 ± 12.9 years) with PE pulmonary artery OS (Qanadli, Mastora, and Mastora central) were assessed by two radiologists. To assess RVD all patients underwent echocardiography within 24 h. Furthermore, RVD on CT was assessed by calculating the right ventricular/left ventricular (RV/LV) diameter ratios on transverse (RV/LVtrans) and four-chamber views (RV/LV4ch) as well as the RV/LV volume ratio (RV/LVvol). OS were correlated with RVD and the occurrence of adverse clinical outcomes (defined as death, need for intensive care treatment, or cardiac insufficiency ≥NYHA III).

Results

Mean Mastora, Qanadli, and Mastora central OS were 26.4 ± 17.7, 12.6 ± 9.9 and 7.5 ± 9, respectively. Echocardiography demonstrated moderate and severe RVD in 10 and 5 patients, respectively. Patients with moderate and severe RVD showed significantly higher Mastora central scores than patients without RVD (14 ± 10.8 vs. 5.9 ± 7.8 [p = 0.05]; 17.6 ± 13.2 vs. 5.9 ± 7.8 [p = 0.038]). A relevant correlation (i.e. r ≥ 0.6) between OS and CT parameters for RVD were only found for the Mastora score and the Mastora central score (RV/LV4ch: r = 0.61 and 0.68, RV/LVvol: r = 0.61 and 0.6). 18 patients experienced an adverse clinical outcome. None of the OS differed significantly between patients with and without adverse clinical outcome.

Conclusion

Pulmonary artery obstruction scores can differentiate between patients with and without RVD. However, in this study, obstruction scores were not correlated to adverse clinical outcome.     

Comparison of diagnostic accuracy of Magnetic Resonance Imaging and Multidetector Computed Tomography in the detection of pelvic fractures

Objective

To compare diagnostic accuracy and interobserver reliability of Magnetic Resonance Imaging (MRI) and Multidetector Computed Tomography (MDCT) in the detection of acute pelvic fractures.

Materials and methods

In 38 consecutive patients (mean age 74.7 years) with a positive finding of anterior pelvis fracture in the conventional X-rays, pelvic MRI and MDCT were performed for further evaluation of pelvic ring fractures. Two radiologists independently read all data sets. Sensitivity and specificity were calculated based on mean scores for each method. Sensitivities of CT and MRI were compared using a paired proportion test (McNemar). Diagnostic validity of both methods was assessed by the interobserver variability using kappa statistics. Combined clinical data and findings from all imaging studies served as the reference standard.

Results

122 fractures were identified in the reference standard (37 sacral, 58 pubic, 22 acetabular, 1 ischial, 4 ilial). On average, MRI detected 96.3% whereas CT detected 77% of all fractures. With regard to sensitivity, MRI proved to be significantly better compared to MDCT (observer 1, p = 0.0009; observer 2, p = 0.0003 by observer 2). In particular, MRI performed better in the depiction of sacral fractures, reaching a sensitivity of 98.6% compared to 66.1% at CT. The interobserver variability was determined to be very good (k = 0.955 for MRI and 0.902 for MDCT).

Conclusion

MRI reaches a significantly higher sensitivity than CT in the detection of acute pelvic fractures, particularly of the sacrum. Especially in elderly patients with suspicion of a sacral fracture and negative results at MDCT, MRI may be considered as the next step in diagnostic workup.     

Accuracy of a new method for semi-quantitative assessment of right ventricular ejection fraction by cardiovascular magnetic resonance: Right ventricular fractional diameter changes

Objective

Longitudinal shortening is traditionally considered the predominant part of global right ventricular (RV) systolic function. Less attention has been paid to transverse contraction. The aim of this study was to evaluate RV transverse motion by cardiovascular magnetic resonance (CMR) in a large cohort of patients and to assess its relationship with RV ejection fraction (RVEF).

Study design

We retrospectively analyzed the CMR scans of 300 patients referred to our center in 2010. RVEF was determined from short axis sequences using the volumetric method. Transverse parameters called RV fractional diameter changes were calculated after measuring RV diastolic and systolic diameters at basal and mid-level in short axis view (respectively FBDC and FMDC). We also measured the tricuspid annular plane systolic excursion (TAPSE) as a longitudinal reference.

Results

Our population was divided into 2 groups according to RVEF. 250 patients had a preserved RVEF (>40%) and 50 had a RV dysfunction (RVEF ≤40%). Transverse and longitudinal motions were significantly reduced in the group with RV dysfunction (p < .0001). After ROC analysis, areas under the curve for FBDC, FMDC and TAPSE, were respectively 0.79, 0.82 and 0.72, with the highest specificity and sensitivity respectively of 88% and 68% for FMDC (threshold at 20%) for predicting RV dysfunction. FMDC had an excellent negative predictive value of 93%.

Conclusion

RV fractional diameter changes, especially at the mid-level, appear to be accurate for semi-quantitative assessment of RV function by CMR. A cut-off of 20% for FMDC differentiates patients with a low (EF ≤ 40%) or a preserved RVEF.     

Multidetector computed tomography predictors of late ventricular remodeling and function after acute myocardial infarction

Background

Despite advent of rapid arterial revascularization as 1st line treatment for acute myocardial infarction (AMI), incomplete restoral of flow at the microvascular level remains a problem and is associated with adverse prognosis, including pathological ventricular remodeling. We aimed to study the association between multidetector row computed tomography (MDCT) perfusion defects and ventricular remodeling post-AMI.

Methods

In a prospective study, 20 patients with ST-elevation AMI, treated by primary angioplasty, underwent arterial and late phase MDCT as well as radionuclide scans to study presence, size and severity of myocardial perfusion defects. Contrast echocardiography was performed at baseline and at 4 months follow-up to evaluate changes in myocardial function and remodeling.

Results

Early defects (ED), late defects (LD) and late enhancement (LE) were detected in 15, 7 and 16 patients, respectively and radionuclide defects in 15 patients. The ED area (r = 0.74), and LD area (r = 0.72), and to a lesser extent LE area (r = 0.62) correlated moderately well with SPECT summed rest score. By univariate analysis, follow-up end-systolic volume index and ejection fraction were both significantly related to ED and LD size and severity, but not to LE size or severity. By multivariate analysis, end-systolic volume index was best predicted by LD area (p < 0.05) and ejection fraction by LD enhancement ratio.

Conclusions

LD size and severity on MDCT are most closely associated with pathological ventricular remodeling after AMI and may thus play a role in early identification and treatment of this condition.     

Enhancement pattern of small hepatocellular carcinoma (HCC) at contrast-enhanced US (CEUS), MDCT, and MRI: intermodality agreement and comparison of diagnostic sensitivity between 2005 and 2010 American Association for the Study of Liver Diseases (AASLD) guidelines

Objective

To evaluate agreement between contrast-enhanced ultrasound (CEUS), multi-detector row computed tomography (MDCT) and magnetic resonance imaging (MRI) for the assessment of typical and atypical enhancement patterns of small hepatocellular carcinoma (HCC); and to compare diagnostic sensitivity of 2005 and 2010 American Association for the Study of Liver Diseases (AASLD) guidelines.

Materials and methods

Between January 2008 and December 2009, we included cirrhotic patients with newly diagnosed 10–20 mm HCC imaged at two contrast-enhanced imaging techniques among CEUS, MDCT, and MRI. Dynamic studies were reviewed by two radiologists to assess enhancement pattern. Percentage of cases with concordant findings and Cohen coefficient (k) were calculated. McNemar's test was used to compare sensitivity between 2005 and 2010 AASLD guidelines.

Results

There were 91 patients (69 M; 22 F; mean age, 68 years) with 96 HCCs, studied with a combination of CEUS and MDCT (n = 59), CEUS and MRI (n = 26), or MDCT and MRI (n = 11). Intermodality agreement for assessment of tumor enhancement pattern was 67% (k = 0.294, P = 0.001). Typical enhancement pattern was detected coincidentally at two imaging modalities in 50 (52%) HCCs. Sensitivity for the diagnosis of HCC increased significantly using the 2010 AASLD (81/96 (84%) vs. 50/96 (52%), P < 0.001).

Conclusions

Agreement between two imaging modalities for the detection of typical tumor enhancement pattern was reached in 52% of cases. The 2010 AASLD guidelines significantly increased the sensitivity for the diagnosis of HCC.     

Multiphase contrast-saline mixture injection with dual-flow in 64-row MDCT coronary CTA

Purpose

To explore the feasibility of multiphase contrast–saline mixture with dual-flow injection technique for visualization of right ventricular (RV) cavity and interventricular septum (IVS) in 64-row multidetector computed tomography (MDCT) coronary angiography.

Materials and methods

Twenty-four patients underwent coronary CT angiography (CTA) imaging with 64-row MDCT. In twelve patients (group A), 60 ml contrast medium (CM) bolus was followed by 40 ml saline, and in the other twelve patients (group B), 50 ml CM bolus was followed by 50 ml contrast–saline mixture at 60:40 ratio. The CM, saline and contrast–saline mixture flow rate were all 5.0 ml/s. Two experienced radiologists measured the CT values of ascending aorta, descending aorta, pulmonary artery and RV, rated the uniformity of RV cavity, the visualization of coronary arteries and IVS independently.

Results

By Kappa test, agreement between the two radiologists was 0.93 and 0.86 concerning the CT value measurements and the grades of the three indexes, respectively. By t-test, the mean CT values of ascending aorta and descending aorta of the two groups had no statistical difference (t = 1.459, P > 0.05; t = 1.619, P > 0.05); while the mean CT values of pulmonary artery and RV cavity had statistical differences (t = 8.316, P < 0.05; t = 10.372, P < 0.05). By two-related rank sum test, according to the visualization of coronary arteries and the uniformity of RV cavity, there were no statistical differences (U = 66.00, P > 0.05; U = 54.00, P > 0.05); while according to the visualization of IVS, group B was better than group A (U = 8.00, P < 0.05).

Conclusion

In coronary CTA, a contrast–saline mixture after CM bolus can provide clear visualization of RV and IVS and LV without impairing coronary CTA image.     

The ratio of right ventricular volume to left ventricular volume reflects the impact of pulmonary regurgitation independently of the method of pulmonary regurgitation quantification

Background

Previous studies have advocated quantifying pulmonary regurgitation (PR) by using PR volume (PRV) instead of commonly used PR fraction (PRF). However, physicians are not familiar with the use of PRV in clinical practice. The ratio of right ventricle (RV) volume to left ventricle volume (RV/LV) may better reflect the impact of PR on the heart than RV end-diastolic volume (RVEDV) alone. We aimed to compare the impact of PRV and PRF on RV size expressed as either the RV/LV ratio or RVEDV (mL/m²).

Methods

Consecutive patients with repaired tetralogy of Fallot were included (n = 53). PRV, PRF and ventricular volumes were measured with the use of cardiac magnetic resonance.

Results

RVEDV was more closely correlated with PRV when compared with PRF (r = 0.686, p < 0.0001, and r = 0.430, p = 0.0014, respectively). On the other hand, both PRV and PRF showed a good correlation with the RV/LV ratio (r = 0.691, p < 0.0001, and r = 0.685, p < 0.0001, respectively). Receiver operating characteristic analysis showed that both measures of PR had similar ability to predict severe RV dilatation when the RV/LV ratio-based criterion was used, namely the RV/LV ratio > 2.0 [area under the curve (AUC)_PRV = 0.770 vs AUC_PRF = 0.777, p = 0.86]. Conversely, with the use of the RVEDV-based criterion (>170 mL/m²), PRV proved to be superior over PRF (AUC_PRV = 0.770 vs AUC_PRF = 0.656, p = 0.0028].

Conclusions

PRV and PRF have similar significance as measures of PR when the RV/LV ratio is used instead of RVEDV. The RV/LV ratio is a universal marker of RV dilatation independent of the method of PR quantification applied (PRF vs PRV).     

Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

Purpose

To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium (³He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT).

Materials and methods

Twenty-seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with HP ³He-MRI and MSCT. Mean age was 55 (±12) years, 18 female and 9 male. Mean ADC from ³He-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test.

Results

Mean ADC and standard deviation values were 0.392 ± 0.119 cm²/s for the established emphysema group and 0.216 ± 0.046 for the pre-clinical emphysema group. MSCT values for the established emphysema group and pre-clinical emphysema group were: EI (%) 11 ± 12 and 0.4 ± 0.6, respectively; 15th percentile (Hounsfield Units (HU)), −956 ± 25 and −933 ± 13, respectively and MLD (HU) −877 ± 20 and −863 ± 15, respectively. Correlations between mean ADC and EI and 15th percentile were both r = 0.90 and for MLD r = 0.59. There was higher correlation between mean ADC and %predicted DLCO (r = 0.90) than between EI and %predicted DLCO (r = 0.76).

Conclusion

HP ³He-MRI correlates well with density measurements from MSCT and agrees better than MSCT with %predicted DLCO which is the PFT most related to emphysema.     

Pancreatic iron stores assessed by magnetic resonance imaging (MRI) in beta thalassemic patients

Purpose

To assess the correlation between MRI findings of the pancreas with those of the heart and liver in patients with beta thalassemia; to compare the pancreas T2* MRI results with glucose and ferritin levels and labile plasma iron (LPI).

Materials and methods

We retrospectively evaluated chronically transfused patients, testing glucose with enzymatic tests, serum ferritin with chemiluminescence, LPI with cellular fluorescence, and T2* MRI to assess iron content in the heart, liver, and pancreas. MRI results were compared with one another and with serum glucose, ferritin, and LPI. Liver iron concentration (LIC) was determined in 11 patients’ liver biopsies by atomic absorption spectrometry.

Results

289 MRI studies were available from 115 patients during the period studied. 9.4% of patients had overt diabetes and an additional 16% of patients had impaired fasting glucose. Both pancreatic and cardiac R2* had predictive power (p < 0.0001) for identifying diabetes. Cardiac and pancreatic R2* were modestly correlated with one another (r² = 0.20, p < 0.0001). Both were weakly correlated with LIC (r² = 0.09, p < 0.0001 for both) and serum ferritin (r² = 0.14, p < 0.0001 and r² = 0.03, p < 0.02, respectively). None of the three served as a screening tool for single observations. There is a strong log–log, or power-law, relationship between ratio of signal intensity (SIR) values and pancreas R2* with an r² of 0.91.

Conclusions

Pancreatic iron overload can be assessed by MRI, but siderosis in other organs did not correlate significantly with pancreatic hemosiderosis.     

Detection of osseous metastases of the spine: comparison of high resolution multi-detector-CT with MRI

Purpose

The aim of the study was to evaluate the diagnostic accuracy of multi-slice-computed tomography (MDCT) for the detection of vertebral metastases in comparison to magnetic resonance imaging (MRI).

Materials and methods

In a retrospective analysis, 639 vertebral bodies of 41 patients with various histologically confirmed primary malignancies were analysed. The MDCT-images were acquired on a 16/64-row-MDCT scanner (Siemens Somatom Sensation 16/64). MRI was performed on 1.5 T scanners (SIEMENS Symphony/Sonata). The MDCT- and MRI-images were evaluated separately by two experienced radiologists in a consensus reading. The combination of MDCT and MRI in an expert reading including follow-up examinations and/or histology as well as clinical data served as the gold standard.

Results

201/639 vertebral bodies were defined as metastatically affected by the gold standard. In MDCT 133/201 lesions, in MRI 198/201 lesions were detected. 68 vertebral bodies were false negative in MDCT, whereas 3 false negatives were found in MRI. 3 false positive results were obtained in MDCT, 5 in MRI. Sensitivity was significantly lower for MDCT (66.2%) than for MRI (98.5%) (p < 0.0001). Specificity was not significantly different for both methods (MDCT: 99.3%; MRI: 98.9%). The diagnostic accuracy resulted in 88.8% for MDCT and 98.7% for MRI.

Conclusion

Although 16/64-row-MDCT provides excellent image quality and a high spatial resolution in the assessment of bony structures, metastatic lesions without significant bone destruction may be missed. The diagnostic accuracy of MRI proved to be significantly superior to 16/64-row-MDCT for the detection of osseous metastases.     

Quantitative assessment of left ventricular systolic wall thickening using multidetector computed tomography

Background

Multidetector computed tomography (MDCT) of the heart provides both anatomical and functional information. The objective of this study was to evaluate the accuracy of quantitative assessment of left ventricular contractile function in relation to two-dimensional transthoracic echocardiography (TTE).

Materials and methods

Sixty-four patients with known or suspected coronary artery disease underwent ECG-gated 64-slice MDCT and TTE. Regional left ventricular contractile function was measured by percent systolic wall thickening (SWT) in 16 myocardial segments using MDCT, and compared with visual evaluation of wall motion score (WMS) by TTE. Global SWT by MDCT was calculated as the mean SWT of all myocardial segments and compared with wall motion index (WMI) by TTE.

Results

Eight hundred and eleven segments (81%) were classified as normokinetic, 142 (14%) as hypokinetic, 41 (4%) as akinetic and 5 (0.5%) as dyskinetic by TTE. A significant inverse linear trend was found between regional SWT by MDCT and WMS by TTE (p < 0.001). Sensitivity and specificity for the identification of regional abnormalities of contractile function were 76% and 78%, respectively. A linear correlation between global SWT by MDCT and WMI by TTE was found (r = −0.8, p < 0.001). Sensitivity and specificity for the identification of WMI > 1.5 using global SWT was 91% and 94%, respectively.

Conclusion

Quantification of systolic wall thickening by MDCT provides functional information, which is well correlated to visual assessment of global left ventricular contractile function by TTE.     

Radiological abnormalities associated with Aspergillus colonization in a cystic fibrosis population

Objective

To determine if sputum colonization with Aspergillus species in patients with cystic fibrosis (PWCF) correlates with radiological abnormalities and/or a reduction in pulmonary function (FEV1).

Methods

We prospectively evaluated 32 PWCF utilizing high resolution computed tomography (HRCT) of the thorax and pulmonary function testing (PFT). The cohort was assessed as two groups: Aspergillus positive (n = 16) and Aspergillus negative (n = 16) based on sputum culture for Aspergillus species. A modified Bhalla scoring system was applied to each HRCT scan by two blinded radiologists.

Results

Aspergillus positive patients had more severe and significant bronchiectasis compared to those Aspergillus negative (p < 0.05). This was most marked in the right upper and lower lobes (RUL, RLL). Total Bhalla score was clinically significant in both groups and approached statistical significance between groups (p = 0.063). No difference in pulmonary function between the groups was detected.

Conclusion

PWCF colonized by Aspergillus species have greater radiological abnormalities undetectable by PFTs. Early radiological evaluation of Aspergillus colonized PWCF is therefore warranted.     

Assessment of cartilage repair after chondrocyte transplantation with a fibrin-hyaluronan matrix--correlation of morphological MRI, biochemical T2 mapping and clinical outcome

Objective

To evaluate change over time of clinical scores, morphological MRI of cartilage appearance and quantitative T2 values after implantation with BioCart™II, a second generation matrix-assisted implantation system.

Methods

Thirty-one patients were recruited 6–49 months post surgery for cartilage defect in the femoral condyle. Subjects underwent MRI (morphological and T2-mapping sequences) and completed the International Knee Documentation Committee (IKDC) questionnaire. MRI scans were scored using the MR Observation of Cartilage Repair Tissue (MOCART) system and cartilage T2-mapping values were registered.Analysis included correlation of IKDC scores, MOCART and T2 evaluation with each other, with implant age and with previous surgical intervention history.

Results

IKDC score significantly correlated with MOCART score (r = −0.39, p = 0.031), inversely correlated with previous interventions (r = −0.39, p = 0.034) and was significantly higher in patients with longer follow-up time (p = 0.0028).MOCART score was slight, but not significantly higher in patients with longer term implants (p = 0.199).T2 values were significantly lower in patients with longer duration implants (p < 0.001). This trend was repeated in patients with previous interventions, although to a lesser extent.

Conclusions

Significant improvement with time from BioCart™II implantation can be expected by IKDC scoring and MRI T2-mapping values. Patients with previous knee operations can also benefit from this procedure.     

Can contrast-enhanced ultrasonography replace multidetector-computed tomography in the detection of liver metastases from colorectal cancer?

Purpose

To compare the sensitivity and specificity of contrast-enhanced ultrasonography (CEUS) and 4-slice multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer (CRC).

Materials and methods

Candidates for this prospective study were 461 consecutive patients referred to the Department of Colorectal Surgery, Aarhus University Hospital with primary or local recurrence of CRC. The patients underwent liver ultrasonography (US), CEUS, MDCT and intraoperative ultrasonography (IOUS). Fine-needle biopsy was performed on all suspicious lesions. The examinations were interpreted blindly and the combination of US, CEUS, biphasic MDCT, IOUS, follow up and biopsy was the gold standard.

Results

Three hundred and sixty-five patients were included. All patients had undergone preoperative US, CEUS and MDCT and 65.5% had received IOUS. The gold standard found liver metastases in 54 patients (14.8%). Multidetector CT found significantly more metastases than CEUS in 15 (28%) of the patients (p = 0.02). In a patient-by-patient analysis MDCT had a non-significantly higher sensitivity in the detection of liver metastases compared to CEUS (0.89 versus 0.80, p = 0.06). The specificity of CEUS (0.98) was slightly better than that of MDCT (0.94) (p = 0.02).

Conclusion

Multidetector CT found significant more metastases than CEUS, and MDCT had in patient-by-patient analysis a non-significant better sensitivity (p = 0.06) in detecting liver metastases in patients with CRC.     

MR imaging of acute pancreatitis: Correlation of abdominal wall edema with severity scores

Objective

To study MRI findings of abdominal wall edema (AWE) in acute pancreatitis as well as correlations between AWE and the severity of acute pancreatitis according to the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation III (APACHE III) scoring system.

Materials and methods

A total of 160 patients with AP admitted to our institution between December 2009 and March 2011 were included in this study. MRI was performed within 48 h after admission. MRI findings of acute pancreatitis were noted, including AWE on the MRI. The abdominal wall area was divided into quarters, and each area involved was recorded as 1 point to score the severity of AWE. The severity of acute pancreatitis was studied using both the MRSI and the APACHE III scoring system. Spearman correlation of AWE with the MRSI and the APACHE III scoring system was analyzed.

Results

In 160 patients with acute pancreatitis, 53.8% had AWE on MRI. The average AWE score was 1.2 ± 1.4 points. The prevalence of AWE was 30.5%, 64.5% and 100% in mild, moderate and severe AP, respectively, according to MRSI. AWE on MRI was correlated with MRSI scores (r = 0.441, p = 0.000). According to APACHE III scores, the averages were 2.0 ± 1.1 and 2.6 ± 1.1 points in mild AP and severe AP, respectively (P = 0.016). AWE was slightly correlated with the APACHE III scores (r = 0.222, p = 0.005).

Conclusion

AWE on MRI in acute pancreatitis is common, which may be a supplementary indicator in determining the severity of AP.